"""连接池管理 API。"""
from typing import List
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import get_db
from app.core.security import require_role
from app.models.user import User
from app.models.instance import Instance
from app.services.connection_pool import get_pool_manager

router = APIRouter(prefix="/pools", tags=["连接池管理"])


@router.get("/instances/{instance_id}/stats")
async def pool_stats(
    instance_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """获取连接池状态。"""
    result = await db.execute(select(Instance).where(Instance.id == instance_id))
    instance = result.scalar_one_or_none()
    if not instance:
        raise HTTPException(status_code=404, detail="数据源不存在")

    manager = get_pool_manager()
    stats = manager.get_pool_stats(instance_id)
    if not stats:
        return {
            "instance_id": instance_id,
            "status": "not_initialized",
            "message": "连接池尚未初始化，将在首次查询时自动创建",
        }

    return stats.to_dict()


@router.post("/instances/{instance_id}/reset")
async def reset_pool(
    instance_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """重置连接池。"""
    manager = get_pool_manager()
    await manager.reset_pool(instance_id)
    return {"message": "连接池已重置", "instance_id": instance_id}


@router.get("/overview")
async def pools_overview(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """所有连接池概览。"""
    manager = get_pool_manager()
    all_stats = manager.get_all_stats()

    return {
        "total_pools": len(all_stats),
        "pools": [stats.to_dict() for stats in all_stats.values()],
    }